The present invention relates to a base structure of a building, capable of improving earthquake-resistant and vibration-proof of the building against earthquake, traffic vibration, etc. and effectively preventing subsidence of ground, and to a construction method thereof.
Vibration due to earthquake, vibration accompanied by passing of large-sized vehicles such as buses and trucks, that is, traffic vibration, or vibration of mechanical operation of machines in works exerts adverse effect on the base of a building, and at the worst case, it causes dip-slip or collapse of the building, or ground subsidence.
Conventionally, to improve earthquake-resistant and vibration-proof of a building against earthquake and vibration due to traffic, etc. and to prevent ground subsidence, there has been adopted a means of increasing the amounts of concrete and reinforcements for constructing the base of a building, a means for supporting the base of the building with piles, or a means of reinforcing soft ground by using a cement based ground improvement material.
The improvement of earthquake-resistant and vibration-proof and the prevention of ground subsidence by the above-described means, however, is not only economically disadvantageous in that a large number of materials must be used to thereby raise the construction cost, but also insufficient to realize the above-described purpose even if a large number of materials are used.
Japanese Patent Laid-open Nos. Hei 9-165758, Hei 9-273160 and Hei 11-256596 have disclosed a base structure of a building, in which a base support formed by a synthetic resin molded foam is laid under the base of the building. Such a base structure is very effective to improve earthquake-resistant and vibration-proof and to prevent ground subsidence.
Since, large earthquake disasters have occurred in recent years, as a starting point of examination, the conventional safety standard has been required to be reviewed, and to meet such a requirement, it is expected to develop a stronger earthquake-resistant base structure of a building.